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Biases in security risk management: Do security professionals follow prospect theory in their decisions?
Get PDFSecurity professionals play a decisive role in security risk decision making, with important implications for security in organisations and society. Because of this subjective input in security understanding possible biases in this process is paramount. In this paper, well known biases as observed and described in prospect theory are studied in individual security risk decision making by security professionals. To this end, we distributed a questionnaire among security professionals including both original dilemmas from prospect theory and dilemmas adapted to the context of incident prevention. It was hypothesised that security professionals dealing with risks and decision making under risk on an almost daily basis would or should be less vulnerable to decision biases involving risks, in particular when framed in terms of incident prevention. The results show that security professionals are vulnerable to decision biases at the same scale as lay people, but some biases are weaker when decision problems are framed in terms of security as opposed to monetary gains and losses. Of the individual characteristics defining experience, only the general education level observably affects vulnerability for biases in security decision making in this study. A higher general education level leads to a significantly higher vulnerability to decision biases. By highlighting the vulnerability of security professionals to decision biases, this study contributes essential awareness and knowledge for improved decision making, for example by different representation of probabilities and uncertainty
On the cost elasticity of inter-regional distribution structures: a case study for the Netherlands
Get PDFSeveral studies show that logistics facilities have spread spatially from relatively concentrated clusters in the 1970s to geographically more decentralized patterns away from urban areas. The literature indicates that logistics costs are one of the major influences on changes in distribution structures, or locations and usage of logistics facilities. Quantitative modelling studies that aim to describe or predict these phenomena in relation to logistics costs are lacking, however. This is relevant to design more effective policies concerning spatial development, transport and infrastructure investments as well as for understanding environmental consequences of freight transport. The objective of this paper is to gain an understanding of the responsiveness of spatial logistics patterns to changes in these costs, using a quantitative model that links production and consumption points via distribution centers. The model is estimated to reproduce observed use of logistics facilities as well as related transport flows, for the case of the Netherlands. We apply the model to estimate the impacts of a number of scenarios on the spatial spreading of regional distribution activity, interregional vehicle movements and commodity flows. We estimate new cost elasticities, of the demand for trade and transport together, as well as specifically for the demand for the distribution facility services. The relatively low cost elasticity of transport services and high cost elasticity for the distribution services provide new insights for policy makers, relevant to understand the possible impacts of their policies on land use and freight flows
Network vulnerability analysis based on the overall and inequity impacts of the distribution of the added travel time to the network users
Get PDFVulnerability has been a major concern in the performance evaluation of transportation networks. In the concept of vulnerability, the key step is to identify the critical link, which are the ones susceptible to severe operational degradation caused by any type of failure. Several studies have been devoted to this issue by introducing indicators that illustrate the network\u27s operational degradation\u27s overall impact. However, the impact of the interrupted network on users can be further evaluated using the inequity perspective. Here, we present a method to assess network vulnerability to operational degradation based on spatial inequity impacts. The importance of a link is determined by calculating the Gini-coefficient of the distribution of added travel time to the users when the link is disabled. Furthermore, the overall impact of link failure is calculated based on the total extra travel time. The final link\u27s importance is determined by the non-dominated sorting method based on the Pareto optimality concept considering both overall and inequity objectives. Measures quantifying overall and inequity impacts of link failure allow planners to determine how this influences the disadvantaged distribution and help them make decisions associated with maintenance plans that consider link failure\u27s equity impact
Multi-objective railway timetabling including energy-efficient train trajectory optimization
Get PDFEnergy-efficient train driving is an important topic to railway undertakings (RUs) for sustainability and cost reduction. The timetable affects the possibilities for energy-efficient train driving by the amount of running time supplements, which is the topic of energy-efficient train timetabling (EETT). The scientific literature on EETT focuses mainly on the balance between total running time and energy consumption. However, in practice RUs consider a trade-off between the total running time, the infrastructure occupation and the timetable robustness, while energy efficiency is not considered. In this paper we consider a multiple-objective timetabling problem at a microscopic infrastructure level that adds energy consumption to the other three objectives. We approach the multiple-objective problem by a brute force search algorithm, where we use two different methods to compute the optimal solution: a weighted sum method and a distance metric method. We apply the method to a Dutch case study on the corridor between the stations Arnhem Central and Nijmegen with alternating Intercity and Sprinter trains, without intermediate overtaking possibilities. The results indicate that there is a balancing relationship between the total running time and energy consumption, without influencing the infrastructure occupation and robustness. The results of the 10 Pareto-optimal solutions show a variation of 5% for the total running time, 18% for the energy consumption, 0.3% for the extended cycle time, and 0.8% for the buffer time. The shortest running time leads to 18% more energy consumption than the longest running time with 5% more running time supplement. In both cases the extended cycle time and buffer time are almost constant. On the other hand, reducing the infrastructure occupation leads to homogenization of the timetable. Therefore, including energy consumption in the multiple-objective can be used to balance the trade-off between total running time and capacity consumption.
Editorial: Special issue of the 8th Symposium of the European Association of Research in Transportation
Get PDFThis special issue presents three selected papers from the 8th Symposium of the European Association of Research in Transportation (hEART) that was held from 4 to 6 September 2019 in Budapest, Hungary. The three contributions reflect the interdisciplinary nature of the conference, covering different areas of transportation research with different methodologies. They also all connect to some of the current challenges of the community, as highlighted by the keynote speakers
Building with Nature: A nineteenth century concept
Get PDFThe concept of “Building with Nature” refers to a harmonious way of creating environments for new living, working and recreation spaces with respect to nature. It also builds resilience to natural events such as storm surges and thus involves the design of infrastructure. This is done with the intention of ensuring the preservation or expansion of environmental and ecological resources, nature, and landscape. Moreover, it considers climate change and sea level rise as well as more frequent and intense storms, resulting in floods and land subsidence. The concept of Building with Nature is strongly connected to an industrialized society. Before the Industrial Revolution, technological advances and engineering, people were forced to live and work according to the rules of nature. This paper seeks to discover what we can learn from 19th century concepts on Building with Nature that are rooted in the pre-industrial era. The paper explores the history of the science of soil and water, in deltaic regions and focuses on the United States and the Netherlands during the nineteenth century. Within these contexts, two key historic figures are positioned, Joseph Raymond Thomassy and Willem Antonie Scholten. By reflecting on the communication between Thomassy and Scholten, the paradigm shift diverging from Building with Nature is exposed and takes on a new and compelling meaning of both an industrial approach and a natural solution to water management
Megaform as Urban Landscape
Get PDFKenneth Frampton closed the honorable Raoul Wallenberg Memoria lecture in 1999 with an address by Vittorio Gregotti in 1983 wherein he asserted that, "The origin of architecture is not the primitive hut, but the marking of ground, to establish a cosmic order around the surrounding chaos of nature." Frampton stated that the technological urbanised region is the new chaos but as architects and urbanists we still have the same task, bringing harmony between the chaos of the technological urbanised space and the chaos of nature. The lecture by Frampton is extremely relevant today. The megaform is an urban landscape, which could be an answer to reverse the altered and controlled nature, or the environmental crisis, towards a new harmony. This is especially urgent in delta regions, which have 12 times the global mean of 47 people per sq km, resulting in a population density of 580 people per sq km. Especially here the inclusion of delta dynamics and at the same time as Frampton proposes: “sustaining a sense of place but also of serving as an effective catalyst for the further development of the region” could offer purpose for the megastructure as human response to the longue durée of the natural system. Frampton mentions in his lecture two deltaic megaforms created by Kenzo Tange in Tokyo and Jaap Bakema the Plan Pampus in Amsterdam. These examples are contextualized and visualized in the section Project by sharing the project Mammoth of Jaap Bakema more in depth that is a megastructure response to the soft and wet soil conditions in the Netherlands: thick water.
This reprint of the Raoul Wallenberg Memoria lecture by Kenneth Frampton (1999) is done with permission of the The University of Michigan A. Alfred Taubman College of Architecture + Urban Planning and Kenneth Frampton, New York
Numerical and small-scale physical modelling of wave transmission by wooden fences
Get PDFMangrove forests, that often act as natural coastal defences, enormously suffered due to ongoing climate change and human disturbances. Thus, it is necessary to have a countermeasure to mitigate the loss of mangroves. Wooden fences are becoming a viable nature-based solution to protect vulnerable replanted mangrove forests. However, the wooden fence\u27s hydraulic characteristics are not yet fully understood due to the complication of branches arrangement. In the present study, a small-scale wave flume modelling of wave damping by a wooden fence was constructed using the inner branches as an inhomogeneous arrangement tested in earlier flow-resistance experiments. The physical model results indicate that the wooden fence is highly effective on wave transmission and that the effectiveness in wave reduction depends on the relative fence thickness, B/Hi. To understand the scale effect on wave transmission further, the numerical model SWASH was used with the laboratory wave data. By applying the prior experiments\u27 drag coefficient on steady flow, the uncalibrated numerical model gave a good agreement with the wave model results, with a root-mean-square error for the total transmitted wave heights of 4.7%. After validation, potential scale effects for small scale tests were determined from scaling simulations at both full scales and the applied 1:5 model scale. These simulations were performed for a fence porosity of 0.81, and different fence thicknesses to understand scale effects between model- and full-scale. Both wave reflection and transmission at model-scale are about 5% higher than full-scale results due to the increased drag coefficient and viscous effects. The effects of fence thickness and porosity were the same in large and small scale, and much larger than the error due to scale effects. Hence testing fence efficiency at physical small scale is regarded as a useful tool, together with numerical modelling
Exploring productive Features of Infrastructure: Social Mobilisation during the Cape Town Water Crisis
Get PDFThis article explores social mobilisation in the context of the 2018 water crisis in Cape Town. Water infrastructure reveals political realities and disciplines, directs and shapes the lives and lifestyles of different populations. The announcement of Day Zero caused various reactions across Cape Town but made clear that the water infrastructure was quotidian and unremarkable whilst working uninterruptedly. The interference of the water infrastructure created an awareness of water and its use across Cape Town. Capetonians developed daily strategies to cope with the situation. These strategies interfered with their daily tasks, impacted personal relationships, and revealed narrations of struggle and privilege. During the water crisis, people became experts on water-related topics and many residents engaged extensively with water realities that affected their own lives and the lives of those around them. Water realities arose from daily challenges which Capetonians were experiencing and as a result, they felt the need to address the issue with vigour, including in the form of social mobilisation, civic activism, and public participation processes
Flooded Cities: A Comparative Analysis of Flood Management Policies in Indian states
Get PDFFlooding is a critical issue affecting many countries worldwide with severe consequences on the lives of their residents. In this paper, we conduct a case study of the flood management policies of India by evaluating their implementation in six Indian states that are affected by recurrent flooding every year. The states selected have major cities located near water bodies and have experienced flooding leading to deaths and displacement besides slowing down economic and community development.
We evaluate how each of the states align their policies to the national level disaster management guidelines for flood management. We find that for policies established at the state level, implementation within the various regions can vary with some urban areas going beyond the state and national guidelines. We find that not all Indian states follow the established national guidelines, and this poses questions on the challenges on having uniform flood management policies for addressing a complex issue
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